On Mar 2 2016, Zak Seidov wrote: > https://oeis.org/A268539 > >Are 2,3,7,17 the only primes in A268539? > >-- >Seqfan Mailing list - http://list.seqfan.eu/ > Yes. Each term of A268539 is of the form (x^2-25)/48 = (x-5)(x+5)/48 where x is an integer. So if x > 53, it must factor... Cheers, Robert